Inhalation exposure to the more volatile PCBs in urban areas, near the Great Lakes, in areas where[unreadable] dredging is occurring, and at landfills and remediation sites has the potential to cause neurological,[unreadable] reproductive, and immunological toxicity in animals and humans. Projects 1, 2, and 3 will investigate the[unreadable] toxicological responses to atmospheric PCBs. We propose an Inhalation Toxicology Core within the isbrp to[unreadable] support these Projects. Our primary goal is to serve the other research support cores and the projects[unreadable] with state-of-the-art animal facilities and rigorously controlled inhalation exposures to realistic[unreadable] mixtures of airborne PCB congeners. In order to achieve this goal, we have established four specific aims:[unreadable] Aim 1) Generate controlled PCB atmospheres in exposure chambers and collect airborne PCBs resulting[unreadable] from vaporization of common industrial PCB mixtures to facilitate the creation of a model exposure[unreadable] mixture, (supports Projects 1, 2, 3, 5 and the Synthesis Core)[unreadable] Aim 2) Perform acute, subacute and subchronic inhalation exposures to laboratory animals to defined[unreadable] mixtures of atmospheric PCBs and to individual congeners, (supports Projects 1, 2, and 3)[unreadable] Aim 3) Provide a rodent vivarium for experimental animals used for the isbrp and execute a quality[unreadable] assurance program to monitor their health and welfare, (supports Projects 1, 2, and 3)[unreadable] Aim 4) Perform necropies on exposed, control and sentinel rodents and distribute tissues to project[unreadable] investigators in the isbrp. (supports Projects 1, 2, and 3)[unreadable] The Inhalation Toxicology Core will be created within the existing Inhalation Toxicology Facility (ITF) of the[unreadable] Environmental Health Sciences Research Center which consists of 6,000 ft2 of contiguous laboratories and[unreadable] offices. The ITF is nationally recognized for innovative animal models and exposure delivery systems. A full[unreadable] array of inhalation toxicology, aerosol science, and bioassay services are rendered. The Inhalation[unreadable] Toxicology Core is well equipped for generating and quantifying PCB vapors or aerosols; for performing[unreadable] nose-only inhalation exposures of rats in acute, subacute or subchronic protocols; and for determining the[unreadable] degree of exposure and response. The development of innovative exposure delivery systems for PCB[unreadable] mixtures representative of atmospheric congeners is an essential concurrent activity.